Polymer–Microbe Interfaces for Enhanced Electron Transfer in Microbial Fuel Cells

The increasing demand for sustainable energy storage has highlighted the limitations of lithium‐ion batteries, including resource depletion, thermal instability, electrode degradation, and limited recyclability. These challenges have stimulated interest in microbial fuel cells (MFCs), which simultaneously generate electricity and treat organic waste through the metabolic activity of electroactive microorganisms. However, their large‐scale application is hindered by inefficient extracellular electron transfer (EET), unstable biofilms, and high interfacial resistance. This review summarizes recent advances in electroactive bacteria and polymeric materials for improving MFC performance. Particular emphasis is placed on conductive polymers, biopolymers, polymer composites, and polymer‐based membranes that enhance microbial adhesion, biofilm stability, and charge transport. The review highlights how polymeric materials facilitate direct electron transfer (DET) by forming conductive bridges between bacteria and electrodes, while mediated electron transfer (MET) is enhanced through redox‐active polymers and electron‐shuttling molecules. Recent developments in polymer–carbon and polymer–metal oxide hybrid materials are also discussed for their roles in improving conductivity, durability, and power generation. Overall, this review provides insights into polymer‐assisted interface engineering for developing efficient, stable, and scalable MFCs for sustainable bioenergy applications.